I want to play with the Voobly patch vs the AI. Is it possible to launch the patched game version without connecting to Voobly every time?

You could, though you should be sure you know what you're doing, as you would be replacing game files you would need to replace back if you wanted to go to the original version again - if you're ready for that, you can take the mod files from the Voobly Mods folder in your game installation folder and replace the originals, which you should always back up somewhere before changing them in case you want to go back.

Thanks, that did the trick

You're welcome, gl&hf